PDepend\Util\Type::initTypeToExtension PHP Method

    private static function initTypeToExtension()
    {
        // Skip when already done.
        if (self::$typeNameToExtension !== null) {
            return self::$typeNameToExtension;
        }
        self::$typeNameToExtension = array('iterator' => '+standard');
        $extensionNames = get_loaded_extensions();
        $extensionNames = array_map('strtolower', $extensionNames);
        foreach ($extensionNames as $extensionName) {
            $extension = new \ReflectionExtension($extensionName);
            $classNames = $extension->getClassNames();
            $classNames = array_map('strtolower', $classNames);
            foreach ($classNames as $className) {
                self::$typeNameToExtension[$className] = '+' . $extensionName;
            }
        }
        return self::$typeNameToExtension;
    }